Blower Apparatus and Method for Packaged Terminal Air Conditioner

ABSTRACT

A blower apparatus designed for PTAC use includes an impeller configured to be capable of rotating about a central axis; a low voltage DC motor arranged to drive the impeller; a housing configured to accommodate the motor and impeller fixed together; an inlet cover which draws fresh air into the apparatus and an outlet port that discharges the fresh air through an outlet port and at least two directional changes perpendicular to the flow of fresh air through the inlet.

FIELD OF THE INVENTION

This invention relates to a blower apparatus and method useful in apackaged terminal air conditioner (PTAC). The subject blower apparatusdraws fresh air from the outdoor environment to be pretreated,pressurized, and then discharged into an air distribution system thatcombines the pretreated, pressurized fresh air with air beingrecirculated inside an identified space in which the indoor section ofthe PTAC is installed in accordance with applicable building codes andregulations.

DESCRIPTION OF RELATED ART

Air conditioner systems, apparatus, methods and designs are disclosed inat least the following United States patents and publications: U.S. Pat.Nos. 3,666,002; 5,992,160; 6,009,716; 7,628,026; 8,757,506; 9,383,115;9,696,044; D618,777; 2005/0224591; and 2008/0230619.

SUMMARY OF THE INVENTION

A centrifugal blower apparatus designed for use in a PTAC includes animpeller with inclined fins or vanes configured to be rotated about acentral axis; a low voltage DC motor arranged to drive the impeller; ahousing configured to accommodate the motor and impeller fixed together;an inlet through which pretreated fresh air is drawn into the blowerapparatus and an outlet through which the pretreated fresh air isdischarged through two perpendicular bends and then combined with insideair being recirculated by the PTAC.

The blower apparatus is constructed to draw fresh air from the externalenvironment to the indoor enclosure for PTAC Series in accordance withknown building code regulations. This blower apparatus arranges to drawfresh air in from one side and discharge it perpendicularly upwardrelative to the inlet port. The low voltage DC motor rotates theimpeller to create suction to draw pretreated fresh air in and thenpressurize and expel the pressurized fresh air out through the outletport to be combined with the inside air being recirculated by the PTAC.The housing provides an accommodation for the impeller to concentratethe drawn in sir and expel it out through the outlet port. The coveracts as an inlet guide to draw fresh air into the suction side of theimpeller.

This blower apparatus can also be used with appropriate modifications inother types of air-conditioners.

BRIEF DESCRIPTION OF THE DRAWINGS

The apparatus of the invention is further described and explained inrelation to the following drawings wherein:

FIG. 1 is a rear perspective of one embodiment of the blower apparatusof the invention;

FIG. 2 is a side elevation view, partially broken away, of the housingof the blower apparatus of FIG. 1 with the cover and impeller removed;

FIG. 3 is a side elevation view, partially broken away, of the housingof the blower apparatus of FIG. 1 with the impeller installed and thecover removed;

FIG. 4 is a top plan view of the blower apparatus of FIG. 1; and

FIG. 5 is a cross-sectional top plan view taken through the impellershaft of the blower apparatus of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the accompanying drawings, FIG. 1 illustrates a perspectiveview of one embodiment of the invention in which blower apparatus 10embodies housing 1, impeller 2, and inlet cover 3.

FIG 5. further illustrates stainless steel shaft 4, durableself-lubricating ball bearings 5, self-adjusting load spring 6, lowvoltage DC motor 7 operatively connected to a feedback control loopcircuit.

When impeller 2 rotates around the horizontal axis of shaft 4, fresh airis sucked in from the side and is discharged from the top. The impelleris driven by a low voltage DC motor to create the rotational actionwhich sucks fresh air in from the outside and discharge it through thedischarge port to be combined with inside air being recirculated throughthe PTAC.

Referring to FIGS. 2 and 5, the angle of the central vertical axisthrough shaft 4 in relation to the outlet port is desirably in the rangeof 4-6 degree, which is designated by the value “X” in FIG. 2.

Housing 1, when coupled with impeller 2, creates a scroll whichgenerates the needed pressure to drive the fresh air out the dischargeport. This scroll configuration is based on the reduction of spacebetween the housing inner walls and the impeller external surface. Theratio of reduction is preferably about 4.2:1, which is shown in FIG. 3as dimension Z1/Z2.

The central location of impeller 2 in reference to the air outlet portis of equal distance between the housing against impeller and impelleragainst the air inlet cover. FIG. 4, dimension Y.

The fins or vanes of impeller are equally spaced from the impellercenter main rib. These air moving fins number 47 per side. The crescentshaped air moving fins height is ratio at 1/10 the size of the impellerdiameter. See FIG. 3, dimension W1/W2.

Referring again to FIG. 1, housing 1, impeller 2 and cover 3 of blowerapparatus 10 are desirably made of durable, heat resistant,anti-microbial rated plastic. The low voltage DC driven motor 7 isdesirably provided with a feedback loop circuit to provide a constantrotation for the impeller, which in turn generates a constant airflowout of blower apparatus 10. Self-lubricating ball bearings 5 act aspivot points for the impeller to maintain a stable low vibrationrotation, which also contributes to low operational noise levels. Theself-adjusting load spring 6 maintains impeller 2 in its centralizedlocation to ensure smooth rotation and proper balance during use.

The stainless steel shaft 4 is desirably integrated with impeller 2during plastic injection to ensure properly secured, durable operation.The structural strength of impeller 2 is centered in the middle with theair moving fins extending from both sides to create a good balancing forimpeller 2 during operation. With proper balance, there is littlevibration and thus a low noise operation for blower apparatus 10.

Low voltage motor 7 desirably runs at 24V DC, a non-life threateningvoltage, to provide electrical safety to users during operation of thePTAC. The two small holes 101 on impeller 7 act as shipping locks when apin is inserted into it as shown in FIG. 1. Rectangular slots 102 (FIG.2) on the lower section of housing 1 act as drainage holes if waterenters blower apparatus 10.

Other alterations and modifications of the invention will likewisebecome apparent to those of ordinary skill in the art upon reading thisspecification in view of the accompanying drawings, and it is intendedthat the scope of the invention disclosed herein be limited only by thebroadest interpretation of the appended claims to which the inventorsare legally entitled.

What is claimed is:
 1. A blower apparatus for use in a packaged terminalair conditioner, the blower apparatus comprising housing, impeller,inlet cover, stainless steel shaft, self-lubricating ball bearings,self-adjusting load spring, and a low voltage DC motor operativelyconnected to a feedback control loop circuit.
 2. The blower apparatus ofclaim 1 wherein the impeller rotates around the axis of the shaft and isdriven by the low voltage DC motor.
 3. The blower apparatus of claim 1wherein the angle of the central vertical axis through the shaftrelative to the outlet port ranges from 4-6 degrees.
 4. The blowerapparatus of claim 1 wherein the housing, when coupled with impeller,creates a scroll which pressurizes the fresh air to drive the fresh airout the outlet port.
 5. The blower apparatus of claim 4 wherein thescroll configuration is based on the reduction of space between thehousing inner walls and the impeller external surface.
 6. The blowerapparatus of claim 5 wherein the ratio of reduction is preferably about4.2:1.
 7. The blower apparatus of claim 1 wherein the impeller iscentered between the housing and the air inlet cover.
 8. The blowerapparatus of claim 1 wherein the impeller has equally spaced fins orvanes equally spaced between the impeller center and the housing.
 9. Theblower apparatus of claim 1 wherein the impeller has 47 fins or vanesper side.
 10. The blower apparatus of claim 1 wherein the ratio of finheight to impeller diameter is about 1:10.
 11. A method for drawingfresh air into a pressurized terminal air conditioner (PTAC) comprisingproviding a fresh air inlet port configured to receive fresh (outside)air, providing a centrifugal blower apparatus disposed in fluidcommunication with the fresh air inlet port, operating the centrifugalblower apparatus to draw fresh air into an impeller disposed thatpressurizes and then redirects and discharges the pressurized airperpendicularly to the incoming air and upwardly from the blowerapparatus into a receiving duct that redirects a flow of pressurizedfresh air to be combined with a flow of inside air being recirculated bythe PTAC.